Patent Literature 1 discloses a conventional four-face formation method of a three-dimensional net-like structure. This method aims to individual formation of a single three-dimensional net-like structure. Melted filaments made of a thermoplastic synthetic resin as the raw material or as the main material are extruded downward from a die having a nozzle with a plurality of holes at an end to freely fall between partly submerged haul-off machines. The three-dimensional net-like structure is manufactured by hauling of the filaments at a lower rate than the rate of the fall. Two pair of haul-off machines arranged to face each other are provided. A rectangle is formed in a direction perpendicular to the extrusion direction by the above two pairs of haul-off machines. The interval between the facing haul-off machines is set to be less than the width of an assembly of the extruded filaments. All the four peripheral faces of the assembly of the filaments are in contact with the haul-off machines before and after submerging of the haul-off machines, so as to form the three-dimensional net-like structure